1. Field of the Invention
The present invention relates to a withdrawal device for the secure withdrawal of a puncture needle from a catheter, in particular from a catheter with a flexible catheter tube.
2. Description of the Related Art
In medicine, catheters are used in various fields for administering drugs which have been dissolved or suspended in fluid. Using catheters medication can be directly administered into the patient's tissue or bloodstream via a puncture site. In order to attach the catheter it is necessary to create an entry into the tissue or bloodstream of the patient by means of a puncture. Various puncture configurations are known for this purpose.
Puncture configurations of the type initially described are especially intended for independent use by the patient, for example, for administering insulin with the aid of an insulin pump.
For puncture configurations featuring a flexible catheter tube and a puncture needle, when the catheter hub is attached to the skin surface of the patient, the underlying tissue is pierced by the puncture needle, while the flexible catheter tube is inserted into the tissue in the process. The patient's stomach area is frequently chosen as the incision site for the puncture configuration. Following insertion, the puncture needle must be withdrawn and removed, so that only the catheter tube remains in the puncture site. The catheter hub is then hooked up to an infusion line and therefore, to medication delivery. On the one hand, the withdrawal of the puncture needle should be effected quickly and safely. On the other, the puncture needle should if possible be encapsulated after withdrawal but at the very least protected against open exposure. This serves to reduce and if possible completely rule out the danger of injury by means of a needle contaminated with bodily fluid and the danger of infection associated therewith.